Water tank with antimicrobial internal liner

ABSTRACT

One or more techniques and/or systems are disclosed for a tank assembly that provides antimicrobial protection to inhibit microbial growth in the interior of the tank body. The tank assembly can comprise a body with a side wall and one or more end walls. An antimicrobial liner can be disposed in the interior of the tank body to cover interior surfaces of the side wall and end wall(s). The antimicrobial liner can comprise an effective amount of an antimicrobial agent to inhibit growth of microbes in the interior of the tank body. In this way, the operation life of the tank assembly may be improved, and problems associated with biofilm fouling may be mitigated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/511,491, entitled ANTIMICROBIAL TANK LINER, filed May 26,2017, which is incorporated herein by reference.

BACKGROUND

Bacteria and other microbes can grow in water containers, which mayresult in serious health concerns for users of such water. Containersthat may hold water can include water towers, water storage tanks,pressure tanks, swimming pools, evaporative condensers, cooling towers,nebulizers, humidifiers, ornamental fountains, and whirlpool spas, toname a few. Water storage tanks and pressure tanks, vessels used tostore, deliver, or otherwise transport water, are often used incommercial buildings, industrial locations, residential buildings, andother areas where potable and/or heated water is desirable for use byoccupants.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key factors oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

One or more techniques and systems described herein can be utilized toprovide a tank assembly with an antimicrobial liner, which may inhibitgrowth of microbes in the interior of a tank body, such as during usefor water storage. As an example, the liner may cover portions of theinterior surfaces of the tank that may be exposed to water duringstorage and other use. In this example, the antimicrobial liner mayinhibit microbe propagation, which may improve operational life of thetank assembly, and provide improved operational performance during itlife.

In one implementation a tank assembly can comprise a body that comprisesa sidewall and a first end wall. Further, in this implementation, thetank assembly can comprise an antimicrobial liner that comprises aneffective amount of an antimicrobial agent to inhibit growth ofmicroorganisms. Additionally, in this implementation, the antimicrobialliner can cover an interior surface of the sidewall and an interiorsurface of the first end wall.

To the accomplishment of the foregoing and related ends, the followingdescription and annexed drawings set forth certain illustrative aspectsand implementations. These are indicative of but a few of the variousways in which one or more aspects may be employed. Other aspects,advantages and novel features of the disclosure will become apparentfrom the following detailed description when considered in conjunctionwith the annexed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a component diagram illustrating an example embodiment of atank assembly, where one or more techniques and/or one or more systemsdescribed herein may be implemented.

FIG. 2 is a component diagram illustrating another example embodiment ofa tank assembly, where one or more techniques and/or one or more systemsdescribed herein may be implemented.

FIG. 3 is a flow diagram illustrating an example implementation whereone or more portions of one or more techniques described herein may beimplemented.

FIG. 4 is a flow diagram illustrating an example implementation whereone or more portions of one or more techniques described herein may beimplemented.

FIG. 5 is a flow diagram illustrating an example method formanufacturing a tank assembly, where one or more portions of one or moretechniques described herein may be implemented.

FIG. 6 is a flow diagram illustrating an example implementation whereone or more portions of one or more techniques described herein may beimplemented.

DETAILED DESCRIPTION

The claimed subject matter is now described with reference to thedrawings, wherein like reference numerals are generally used to refer tolike elements throughout. In the following description, for purposes ofexplanation, numerous specific details are set forth in order to providea thorough understanding of the claimed subject matter. It may beevident, however, that the claimed subject matter may be practicedwithout these specific details. In other instances, structures anddevices are shown in block diagram form in order to facilitatedescribing the claimed subject matter.

In one aspect, a tank assembly can be devised that comprises anantimicrobial liner in at least a portion of the internal chamber of thetank. In this aspect, for example, liquids contained in the interiorchamber of the tank assembly can be exposed to the antimicrobial liner,which may mitigate propagation of microbes in the internal chamber. Inthis way, for example, mitigation of the buildup of microbes that couldfoul the desired operation of the tank assembly is performed. That is, abuildup of microbes can result in advanced deterioration of portions ofthe tank assembly, and/or may create masses that clog and reduceperformance of the tank assembly. Therefore, in one implementation, thepresence of the antimicrobial liner may improve the operational life andperformance of the tank assembly. It is to be appreciated that the tankassembly can be, but is not limited to, use with a well system, potablewater supply system, heated water system, expansion tank system, cisternstorage system, retention tank system, or other commercial andresidential water supply, storage and retention systems, among others.

In one implementation, in this aspect, a tank assembly can comprise abody that comprises a sidewall and a first end wall. Further, in thisimplementation, the tank assembly can comprise an antimicrobial linerthat comprises an effective amount of an antimicrobial agent, effectiveto inhibit growth of microorganisms. Additionally, the antimicrobialliner is disposed in the tank assembly to cover an interior surface ofthe sidewall and an interior surface of the first end wall.

In one implementation, the effective amount of the antimicrobial agentin the antimicrobial liner can be in the range of 0.5% to 12% by weightof the antimicrobial liner. In one implementation, the effective amountof the antimicrobial agent in the antimicrobial liner can be in therange of 1% to 10% by weight of the antimicrobial liner. In oneimplementation, the effective amount of the antimicrobial agent in theantimicrobial liner can be in the range of 2% to 8% by weight of theantimicrobial liner. In one implementation, the effective amount of theantimicrobial agent in the antimicrobial liner can be in the range of 3%to 7% by weight of the antimicrobial liner. In one implementation, theeffective amount of the antimicrobial agent in the antimicrobial linercan be in the range of 4% to 6% by weight of the antimicrobial liner. Inone implementation, the effective amount of the antimicrobial agent inthe antimicrobial liner can be in the range of 2% to 4% by weight of theantimicrobial liner. It is to be appreciated that the effective amountof antimicrobial agent in the antimicrobial liner can be selected withsound engineering judgment without departing from the intended scope ofcoverage of the embodiments of the subject innovation.

In one implementation, the antimicrobial agent can comprise asilver-based agent. As an example, a silver ion compound (e.g.,comprising silver salts) may be utilized to act as the antimicrobialagent. For example, silver salts can release silver ions, which areknown to have an antimicrobial effect by disrupting the propagation ofmicrobes, such as bacteria, algae, and other microbes. Other effectiveantimicrobial agents may be employed in the liner to provide a desiredantimicrobial effect. As an example, an effective amount can be anyamount of the antimicrobial agent that can inhibit growth ofmicroorganisms in the presence of water in the tank assembly.Advantageously, some implementation described herein provide anantimicrobial liner having an effective amount of an antimicrobial agentwithin standard regulatory safety limits, and can be at an amount whichdoes not negatively impact the mechanical properties of the liner andthe assembly.

In one implementation, the antimicrobial liner can comprise apolymer-based material. As one example of a polymer-based material,polypropylene may be used in the liner. Other suitable polymers may beselected for use in the liner, selected based on sound engineeringprinciples. As an example, several types of thermoplastics can be used,such as: acrylic, ABS, nylon, polylactic acid, polybenzimidazole,polycarbonate, polyether sulfone, polyoxymethylene, polyetheretherketone, polyetherimide, polyethylene, polyphenylene oxide, polyphenylenesulfide, polystyrene, polyvinyl chloride, and Teflon. Further, severaltypes of thermosetting plastics may be used, such as: various resins,rubbers, epoxy resins, silicone, polyesters resin, and others. In thisimplementation, the polymer-based material may be used to produce asolid liner applied to or inserted into the inner surface of the tank;or the polymer-based material may be used to produce a liquid-typeproduct applied to the inner surface of the tank and cured.

In one implementation, the polymer-based material can comprise a plasticthat is capable of withstanding temperatures near freezing, up to atleast 212° F., and/or reduced or elevated pressures, without loss ofpreferred characteristics, such as by substantially maintaining itsshape, condition and position. For example, the tank assembly may beutilized in a hot water system, a chilled water system, or a pressurizedwater system, and may be subjected to reduced or elevated temperatures,and/or pressures.

In one implementation, the antimicrobial liner may comprise apolymer-based sheet that is formed to fit the internal shape of thebody. That is, for example, the polymer-based sheet can be formed by anysuitable technique known to the art; such as, vacuum forming, injectionmolding, etc. In this implementation, the resulting formed sheet can beinserted into the tank to cover at least an interior surface of thesidewall and an interior surface of the first end wall. In anotherimplementation, the antimicrobial liner may comprise a coating that isapplied to the interior surface of the tank and cured, providing a linerthat is substantially permanently bonded to the interior surface of thetank. In this implementation, the antimicrobial liner coating can beapplied to the interior surface of the tank to cover at least aninterior surface of the sidewall and an interior surface of the firstend wall.

In one implementation, the tank assembly can comprise a first portioncomprising the first end wall, and a second portion comprising a secondend wall of the body of the tank assembly. In one implementation, thefirst and second portions may be divided by a flexible membrane, such asa bladder. As an exemplary implementation, the first portion may beconfigured to receive (e.g., and hold, and release) liquid, such aswater; and the second portion may be configured to receive (e.g., andhold, and release) gas, such as air. As an example, the tank assemblycan comprise a pressure tank, like those used in well water systems(e.g., and other type of water systems), where pressurized air acting onthe bladder is utilized to create pressure on the water in order togenerate water pressure for use by occupants. In this implementation,the antimicrobial liner may merely be disposed in the first portion(e.g., holding the water), covering the interior surface of first endwall and the interior surface of the portion of the side wall in thefirst portion of the body. In other implementations, such as tanks thathold liquids (e.g., water), the antimicrobial liner may cover a largerarea (e.g., or even the entirety) of the interior surface of the tankbody. It is to be appreciated that the first portion can be configuredto receive and store a first material and the second portion can beconfigured to receive and store a second material, wherein the firstmaterial or the second material can be, but is not limited to being, asolid, a gas, a liquid, a vapor, a portion of air, a mixture of waterand a cleaning agent, a portion of sanitizing agent, a purifying agent,a CO₂, a water, a portion of sewage, a combination thereof, amongothers.

In one implementation, the flexible membrane can comprise anantimicrobial agent, such as one or more of those described above. Inthis implementation, for example, one or more microbial agents can beintegrated into the material used to construct the membrane, such as inthe concentrations described herein. In this way, for example, themembrane may also provide for mitigation of microbial growth in theinterior of that tank. In one implementation, the antimicrobial agentcan be incorporated merely at the surface of the membrane that isexposed to stored water. That is, as an example, the first portion ofthe tank body can be used to store water, and the membrane surfaceexposed to the interior of the first portion may comprise and effectiveamount of antimicrobial agent. Further, as an example, the membrane canbe constructed to comprise a smooth surface that may help to mitigatepropagation of microbes. Additionally, in one implementation, themembrane can comprise a blue color that may indicate an amount of agentpresent, and may be used to emit blue light to help inhibit microbialgrowth.

In one implementation, the first end wall of the tank body can comprisean orifice that is formed to allow the flow of water into and/or out offirst end wall. That is, for example, water can flow into the interiorof the tank through the orifice in the first end wall; water can bestored in the interior of the tank body, and water can flow out of theinterior of the tank body through the orifice in the first end wall.Further, in this implementation, the antimicrobial liner can comprise anorifice that is formed to allow the liner to be aligned with the orificeof the first end wall. That is, for example, the antimicrobial tankliner can cover the first end wall, but have an opening at the orificeto allow liquid (e.g., water) to flow into the interior of the tankbody, through the orifice of the first end wall.

In one implementation, the tank assembly can comprise a flow diverterthat is operably disposed at the orifice of the first end wall; and theflow diverter can be configured to circulate fluid in the tank assemblyin operation. That is, for example, the flow diverter can directincoming water flow in a way that provides continued circulation of thewater (e.g., around the interior of the tank body) while water is beingintroduced into the tank. In this way, for example, circulation of thewater can mitigate stagnation of water in the tank, which can improveinhibition of microbe growth on interior surfaces. In thisimplementation, the flow diverter can be disposed at the orifice of thefirst end wall, and through the orifice of the antimicrobial liner. Itis to be appreciated that the flow diverter can be located at a positioninside the tank assembly and the position of the flow diverter at thefirst end wall is not to be limiting.

In one implementation, the antimicrobial liner can be configured to havea smooth outer finish, facing the interior of the tank body. That is,for example, the face of the liner that comes in contact with the storedwater can have a very smooth finish that is configured to mitigatemicrobial growth. For example, microscopic pitting in a finish can be anucleation site (e.g., a site of attachment) for microbial growth,giving the microbes a location to land and initiate growth. In thisimplementation, the interior finish of the antimicrobial liner can besmooth enough to mitigate these nucleation sites, thereby inhibitingmicrobes from attachment and growth. For example, the smooth finish maybe obtained by a combination of the appropriate type of materials chosento form the liner, and the type of application and finishing. Soundengineering principles can be utilized to select the appropriatematerials, application, and finishing to achieve a known result. Forexample, a microbe may have a characteristic beneficial for growth ornucleation and the antimicrobial surface or composition can be createdto eliminate or reduce such beneficial characteristic.

In one implementation, the antimicrobial liner can comprise a color. Inone implementation, the color can provide an indicator of theconcentration of the antimicrobial agent present in the antimicrobialliner. In this implementation, a darker color can be indicative of ahigher concentration of the antimicrobial agent. As one example, thecolor indicator can be blue; and, the darker the blue can indicate ahigher concentration of the antimicrobial agent in the liner. In thisexample, a light blue can indicate a low concentration (e.g., 2% byweight), and a darker blue can indicate a higher concentration of theantimicrobial agent (e.g., 4%). In one implementation, the blue colormay be used in the antimicrobial liner so that merely blue light isemitted from the liner (e.g., reflected, refracted, or collimated). Asan example, blue light is known to inhibit microbial growth in somemicrobes. Additionally, the blue color can be used to improve good willof user of the tank assembly, for example, as blue color is oftenassociated with clean water. It is to be appreciate that the blue colorcan be, but is not limited to, light blue, dark blue, teal, turquoise,aqua, cerulean, sea foam, aqua marine, a combination thereof, amongothers.

In one implementation, the tank assembly may comprise a valve that isoperably disposed in the second end wall. In this implementation, thevalve may be configured to allow air (e.g., under pressure) to beintroduced into the second portion of the tank body. As an example, forembodiments associated with a water pressure tank, the valve can be usedto pressurize the second portion, by introducing pressurized air, whichcan force the dividing membrane (e.g., bladder) to apply pressure to thefirst portion of the tank body. In this way, water disposed in the firstportion of the tank body will become pressurized based on the amount ofair (e.g., and pressure) introduced through the valve in the second endwall.

In another aspect, the tank assembly may comprise polymer-based walls,and/or composite material walls. That is, for example, the tank assemblymay comprise a polypropylene tank, such as one that is molded into atank form, and configured to store liquids such as water. As anotherexample, thank assembly can comprise composite material tank that ismolded into a tank form, for example, comprising fiberglass and/orcarbon fiber or a graphite-based composite. In this aspect, theantimicrobial agent may be incorporated into the material used toconstruct the tank, for example, instead of (or including) a separateantimicrobial liner.

In one implementation, in this aspect, the tank assembly can comprise aside wall and one or more end walls, composed of a polymer-basedmaterial, such as one or more of those described above. For example, apolymer-based material can be constructed into a tank form usingblow-molding, roto-molding, 3D printing, injection molding,thermoforming, extrusion and stamping, and other well-known techniquesfor forming polymer tank forms. In this implementation, an antimicrobialagent can be added to the base material used to create the tank form,resulting in the antimicrobial agent being disposed at an inner surfaceof the tank body. As another example, the another example, theantimicrobial agent can be added as a layer to the internal surface ofthe polymer tank body.

In another implementation, in this aspect, the tank assembly cancomprise a side wall and one more end walls composed of a compositematerial, such as fiberglass, carbon fiber, graphite-base material. Forexample, a composite material can be used to create a tank form usingwell-known composite forming techniques; and, two or more of thematerials may be used in combination to form the tank body. In thisimplementation, the an antimicrobial agent can be added to the basecomposite material, and/or the resin/binder material, used to create thetank form, resulting in the antimicrobial agent being disposed at aninner surface of the tank body. As another example, the another example,the antimicrobial agent can be added as a layer to the internal surfaceof the composite tank body.

The following are descriptions of several exemplary implementations,along with illustrative example described in the FIGURES, in furtheranceof the details described above. It should be noted that these examplesare used to demonstrate one or more aspects of the inventive concept,and should not be construed to limiting the inventive concept in anyway.

While embodiments herein are described in the context of a well tank,the antimicrobial liners shown and described herein can also be used inother tank assemblies, such as an expansion tank or a retention tank.

As used herein, masterbatch may refer to a solid or liquid additive forplastic or a coating used for imparting certain properties and/orcharacteristics to plastics or coating (e.g., antimicrobial properties,color, etc.).

As used herein, Let Down Ratio (LDR) may refer to the level at which amasterbatch is incorporated into a base resin, polymer, or coatingcompound. For example, an LDR of 4% refers to a composition having 96%polymer and 4% masterbatch.

Referring now to the drawings, FIG. 1 depicts an exemplary tank assemblyin which an antimicrobial liner can be incorporated. FIG. 1 shows a tankassembly 100 (e.g., a well tank), designed for use in conjunction with awell pump or the like, and can help to enhance and deliver a relativelyconsistent pressurized water supply to occupants of a home or commercialproperty.

In this implementation, the tank assembly 100 can include a highstrength steel sealed outer shell 102 (e.g., the side wall) with aninlet/outlet port 104 (e.g., the orifice in the first end wall) locatedat the base of the shell (e.g., the first end wall), and an upper airvalve 106 (e.g., the valve in the second end wall). The interior of theshell can be divided into two chambers (e.g., the first portion and thesecond portion). The upper chamber 108 can contain pressurized air. Thelower chamber 110 can contain a tank liner 112 (e.g., a polypropyleneliner), which stores potable water. The upper chamber 108 and lowerchamber 110 can be separated by a diaphragm 114 (e.g., the flexiblemembrane, or bladder) which can provides a diaphragm seal 116, and canbe used to pressurize the lower chamber 110 as a function of the airpressure in the upper chamber 108.

In operation, for example, the well tank assembly 100 can be integratedwith a well pump which is triggered by a switch to pump water into thelower chamber 110 through the inlet/outlet port 104 when the airpressure falls to a lower threshold pressure (e.g., which corresponds toa low level of water). The pump will stop when the system reaches apreset upper air pressure. When water is demanded by the system'splumbing, the air pressure in the upper chamber 108 transmits a forcethrough the diaphragm 114 against the water in the lower chamber 110,pushing the water into the plumbing system through the inlet/outlet port104. Once the water is consumed and the pressure reduces, a new cyclebegins. The inlet/outlet member 104 of the tank assembly 100 isconfigured such that water either moves into the system through theinlet/outlet 104 when the pump is engaged, or moves out of the systemthrough the inlet/outlet 104 when there is demand.

FIG. 2 illustrates an exploded view of one implementation of a watertank assembly 100, for example, as shown and described in the context ofFIG. 1 above. The upper chamber 108 can include an upper cylindricalbody 202 having a side wall 204 and an end wall 206, which is providedwith an orifice (not explicitly shown-covered by a cap 208). The lowerchamber 110 can include a lower cylindrical body 210 having a side wall212 and an end wall 214 which is also provided with orifice 216.

The interior surface of the lower end wall 214 and the lower portion ofthe lower side wall 212 can be covered by a liquid-imperviousantimicrobial liner 218, which may be composed of a polymer-basedmaterial that is capable of withstanding elevated or reducedtemperatures, and/or elevated and reduced pressures. In one embodiment,the liner can comprise a solid sheet that has been formed and insertedinto the lower portion. In this embodiment, the solid sheet liner can bebonded to the interior surface of the lower chamber 110, or may merelybe placed in a form fitting disposition in the lower chamber 110. Inanother implementation, the antimicrobial liner 218 may be applied to(e.g., sprayed on, painted on, rolled on or otherwise applied) the innersurface of the lower chamber 110. In this implementation, the appliedliner can be cured after application, and form a substantially permanentbond with, and covering, the inner surface of the lower chamber 110. Asan example, the applied liner can comprise a powder coating, a liquidcoating, or a plated coating.

In embodiments herein, the antimicrobial liner 218 can include anantimicrobial agent at an effective amount, for example, in the range of1% to 8% by weight of the liner, or in the range of 2% to 4% by weightof the liner. An effective amount is any amount of the antimicrobialagent that can inhibit growth of microorganisms in the presence of waterin the tank, microorganisms such as Escherichia coli, Staphylococcusaureus, and Legionella. Advantageously, embodiments herein provide anantimicrobial liner having an effective amount of an antimicrobial agentwithin the regulatory safety limits and at an amount which does notnegatively impact the mechanical properties of the liner and theassembly. The antimicrobial agent used in embodiments herein can be asilver-based antimicrobial agent, incorporated into the liner during theprocess of manufacturing the liner. Notably, the amount of antimicrobialagent used in the liner 218 affects the color of the antimicrobial liner218. That is, the color of the antimicrobial liner 218 is correlated tothe effective amount of the antimicrobial agent such that the colordarkens as the effective amount of the antimicrobial agent increases.For example, as the amount of the antimicrobial agent used in theantimicrobial liner 218 increases, the color of the antimicrobial liner218 changes from lighter shades of blue to darker shades of blue. Inembodiments, the blue is a phythalocyanine blue, also known as “thaloblue”, as this blue color exhibits a strong color, tictantorialstrength, and excellent resistance properties to acid, alkali, solvent,lightfastness and weatherability. Phythalocyanine blues are formulatedand added into polymer masterbatches such as those described herein toprotect the product. The amount of thalo blue added to the masterbatchcan be correlated to the effective amount of antimicrobial agents addedsuch that the color of the liner increases as the effective amount ofantimicrobial agent increases. In an embodiment, the blue formulatedinto the masterbatch can be a separate additive that is not part of theantimicrobial agent. In embodiments herein, the liner comes in contactwith potable water, acids, alkali, and solvents that are commonly foundin drinking water supplies. The liner formulated with thephythalocyanine blue emits blue light wavelengths having a greatereffect on inhibiting bacterial and fungal growth. Advantageously, thecombination of the antimicrobial agent with the blue liner provides agreater effect on bacteria efficacy than either alone. Furthermore, alight blue color is used as this color generally improves consumerperception of the quality of taste in a phenomenon known as synesthesia.That is, blue is related to a notion that is described in terms ofclean, fresh, and bacteria free.

The antimicrobial liner 218 described herein can provide for a reductionof biofilm growth which can physically restrict flow paths. Biofilm withanaerobic population may indicate that the growth is advanced as it canbe more prevalent in oxygen-depleted areas, which renders areas such asinside a water tank under pressure to greater susceptibility of biofilmgrowth. The antimicrobial liner 218 can have a great affect in thisenvironment. The antimicrobial agent used in the antimicrobial liner 218in conjunction with flow diverter, helps reduce biofilm growth byenhancing circulation within the tank to increase bacteria contact withthe antibacterial liner surface. Moreover, using the antimicrobial agentin conjunction with a moving diaphragm ensures that bacteria and slimeare sloughed off the surface of the liner for biofilm reduction on theliner surface. Biofilm can scale and form with biological material andminerals from deposits in water or adhesion of particles such as sand.Reduction of the biofilm allows the diaphragm to cycle naturally, andalso avoids abrasion of the diaphragm and avoids creating abrasivesurfaces thereby improving the lifespan of the diaphragm. Furthermore,the antibacterial liner 218 provides for reduction of corrosion in thetank and vicinity by maintaining clean bacteria-free surfaces, asbacteria can affect iron and stainless steel surfaces to a point wherethe surfaces are susceptible to pitting corrosion. The surface of theantibacterial liner 218 is made to be smooth so as to make it harder tofor bacteria to grow, as rough surfaces are easier for slime to form andfor bacteria to grow.

The antimicrobial liner 218 can be manufactured by any suitabletechnique known to the art; such as, vacuum forming, injection molding,etc. Exemplary methods of producing the antimicrobial liner 218 will befurther delineated below in the context of FIGS. 3 and 4.

The antimicrobial liner 218 is configured to cover an interior surfaceof the sidewall 212 and an interior surface of the end wall 214. Theantimicrobial liner 218 is formed with an orifice 302 which mates withorifice 216 in end wall 214 of lower cylindrical body 210. The portionof liner 218 adjacent the orifice 302 is clamped to lower end wall 214,welded, brazed or otherwise suitably connected to tank assembly 100 andadapted to connect tank assembly 100 with the water system of which itforms a part. The orifice 216 and orifice 302 are configured to bealigned with inlet/outlet 104 of FIG. 1 for entry and exit of water inthe tank assembly 100.

Flexible diaphragm 114, formed of butyl rubber or other suitableelastomers, is disposed inside of lower cylindrical body 210 and isadapted to conform to the shape thereof. An exemplary manner in whichdiaphragm 114 is secured to lower cylindrical body 210 can be found inU.S. Pat. No. 5,386,925. Such features and content disclosed in U.S.Pat. No. 5,386,925 are incorporated herein by reference

When installed, well tank assembly 100 is supported on stand 304. Stand304 has a cylindrical side wall 306 which allows fitting 308 to extendbelow end wall 214 of the lower cylindrical body 210. Side wall 306includes a cutout 310 for allowing the water supply/return line 88 toextend from the fitting 308 to the exterior of the tank assembly 100. Inanother embodiment, the tank assembly 100 can be supported from aceiling, wherein a portion of a plumbing system or a bracket can attachto at least one of the upper cylindrical body 202 or the lowercylindrical body 210.

A flow diverter insert 312 is positioned at least partially withinorifice 314 of fitting 308. The orifice 314 is configured to be alignedwith orifice 302 of liner 218 and orifice 216 of lower end wall 214. Theflow diverter insert 312 is configured to circulate water within thetank and is further described in U.S. Pat. No. 9,004,102. Such featuresand content disclosed in U.S. Pat. No. 9,004,102 are incorporated hereinby reference.

FIG. 3 shows an exemplary method of manufacturing the antimicrobialliner 218 for use in the well tank assembly 100 shown and describedabove in the context of FIGS. 1 and 2. As shown, masterbatch 304includes an antimicrobial additive 302 that can be incorporated withplastic resins during molding and provide a biocide treatment to controlmicroorganisms. Regrind 306 can include scraps of antimicrobial resinmasterbatch liners. The masterbatch 304 and regrind 306 are processedtogether in a mixer, such as a hopper 306 to form an antimicrobial resincomposition to be used in making the antimicrobial liners describedherein. The masterbatch 304 can be present at 50% or more by weight ofthe composition, and the regrind can be present at 50% or less by weightof the composition. The composition is then extruded through an extruder308 and provided to a vacuum former 310. The antimicrobial liner 312 isformed, for example, by process of vacuuming forming. The scraps 314left from the process of producing the liner 312 is treated as regrind316 to be used in as regrind 306 in another process to manufacture theantimicrobial liner. While the process shown and described in FIG. 3uses vacuum forming to produce the antimicrobial liner 312, othersuitable processes such as injection molding may be used in otherembodiments.

FIG. 4 shows another method of manufacturing the antimicrobial liner 218for use in the well tank assembly 100 shown and described above in thecontext of FIGS. 1 and 2. Masterbatch 404 can include an antimicrobialagent 402, for example, a silver based antimicrobial agent (e.g., silverions). As shown, the masterbatch includes a LDR of 4%, but theantimicrobial gent 404 can be present in the masterbatch at 1% to 8% byweight of the composition, and can be present at 2% to 4% by weight ofthe composition. The virgin material 406, which does not include anantimicrobial additive, can include a base resin 404, such aspolypropylene or other suitable plastics. The virgin material 406 can bepresent in the composition at greater than or equal to 50% by weight ofthe composition. Regrind 408 can include regrinds 414 and 416, and theregrind 408 can be present in the composition at 46% or less by weightof the composition. The masterbatch 404, virgin material 406 and regrind408 are processed in a mixer, such as hopper 420, to form anantimicrobial composition for use in making the antimicrobial linerdescribed herein. The composition is then extruded through an extruder422 and provided to a vacuum former 424. The antimicrobial liner 412 isformed, for example, by process of vacuuming forming. Scrap 418 is scrapfrom processing of the virgin material 406. Scrap 426 is scrap fromprocessing of the masterbatch 404 material, which contains antimicrobialagents. The scraps 418 and 426 left from the process of producing theliner 412 is then treated as regrinds 414 and 416, respectively, to beused in as regrind 408 in another process to manufacture theantimicrobial liner. While the process shown and described in FIG. 4uses vacuum forming to produce the antimicrobial liner 412, othersuitable processes such as injection molding may be used in otherembodiments.

Advantageously, the antimicrobial liners described above show an abilityto reduce the growth of common fungus, algae, & bacteria. Furthermore,taste and odor results revealed that the antimicrobial agent in theliners was undetectable.

For example, an antimicrobial liner produced according to the methodsdescribed herein with a 4% LDR repeatedly performed up to log 1 efficacyreduction against legionella, and antimicrobial efficacy against both E.coli and S. aureus as their activity values exceeded the standard valueof log 2, which means this application has a greater than 99% bacterialreduction rate. When bacteria contact the surface of the antibacterialliner, reactions with the silver ion rendered the bacteria inert, whichare then swept away during tank usage. This demonstrated its ability tobe an effective antimicrobial solution against common microorganisms andlegionella. The benefit of having such an antibacterial liner ensuresthat even if a water system has a problem with bacteria, the tank willbe protected and will not further propagate the issue.

In one aspect, a method of manufacture can be devised for manufacturinga tank assembly. In this aspect, the tank assembly can be manufacturedwith an antimicrobial liner, and used to inhibit growth of microbes inthe interior of the tank assembly. In this way, for example, theoperational life of the tank assembly can be increased, and potentialoperation problems associated with fouling due to microbes can bemitigated.

FIG. 5 is a flow diagram illustrating an exemplary method 500 formanufacturing a tank assembly. The exemplary method 500 begins at 502.At 504, a tank body comprising a side wall and a first end wall isconstructed. At 506, an antimicrobial liner is installed in the tankbody so that the antimicrobial liner covers an interior surface of thesidewall and an interior surface of the first end wall. At 508, theantimicrobial liner comprises an effective amount of an antimicrobialagent to inhibit growth of microorganisms. Having installed theantimicrobial liner in the tank body, the exemplary method 500 ends at510.

FIG. 6 illustrates another implementation of an example method 600 formanufacturing a tank assembly. The example method 600 begins at 602. At604, the tank body comprising a side wall and a first end wall can beconstructed. At 606, the antimicrobial liner can be constructed.Constructing the antimicrobial liner can comprise, at 608, mixing theeffective amount of antimicrobial agent with a polymer resulting in aantimicrobial agent and polymer mix. The effective amount of the agentcan comprise agent in the range of 0.5% to 12% by weight of theantimicrobial liner. Further, at 610, constructing the antimicrobialliner can comprise heating the mix resulting in a heated mix. At 612,the heated mix can be formed into a sheet; and at 614, the sheet can beformed into a shape that will cover the side wall and first end wall ofthe interior of the tank body. At 616, the antimicrobial liner can beinstalled in the tank body to cover the interior surface of the sidewalland an interior surface of the first end wall. Having installed theliner in the tank body, the example method 600 ends at 618.

In an embodiment, the antimicrobial liner can be a paint coating. Forinstance, the paint can be an additive within the paint to provideantimicrobial features for the liner or an inside of a tank assembly.The additive can be further included with epoxy. For instance, thepolypropylene can be based with antimicrobial liner versus epoxy baseused for the paint on protection. In another embodiment, theantimicrobial can be used with aerosol. In another embodiment, theantimicrobial can be a molded liner or a paint with antimicrobial agentadded, wherein the paint can further be aerosol. For instance, theantimicrobial agent can be done with an aerosol technique to be sprayedonto a material. In another embodiment, the antimicrobial agent can bemixed into the internal paint (e.g., such an epoxy). The antimicrobialagent (e.g., additive to paint or incorporated into a liner) protectsthe product by preventing growth while not treating water. In anotherembodiment, the antimicrobial agent prevents growth while also treatingwater.

In another embodiment, the blue pigment can be mixed with epoxy to coatan interior of a tank assembly. In another embodiment, a top layer of amulti-layer air cell can include the antimicrobial liner or agent. Inanother embodiment, a high density polypropylene tank or bottle inindirect fired hot water storage can include the antimicrobial liner oragent.

Moreover, the word “exemplary” is used herein to mean serving as anexample, instance or illustration. Any aspect or design described hereinas “exemplary” is not necessarily to be construed as advantageous overother aspects or designs. Rather, use of the word exemplary is intendedto present concepts in a concrete fashion. As used in this application,the term “or” is intended to mean an inclusive “or” rather than anexclusive “or.” That is, unless specified otherwise, or clear fromcontext, “X employs A or B” is intended to mean any of the naturalinclusive permutations. That is, if X employs A; X employs B; or Xemploys both A and B, then “X employs A or B” is satisfied under any ofthe foregoing instances. Further, At least one of A and B and/or thelike generally means A or B or both A and B. In addition, the articles“a” and “an” as used in this application and the appended claims maygenerally be construed to mean “one or more” unless specified otherwiseor clear from context to be directed to a singular form.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features, ranges, and acts described above aredisclosed as example forms of implementing the claims.

Also, although the disclosure has been shown and described with respectto one or more implementations, equivalent alterations and modificationswill occur to others skilled in the art based upon a reading andunderstanding of this specification and the annexed drawings. Thedisclosure includes all such modifications and alterations and islimited only by the scope of the following claims. In particular regardto the various functions performed by the above described components(e.g., elements, resources, etc.), the terms used to describe suchcomponents are intended to correspond, unless otherwise indicated, toany component which performs the specified function of the describedcomponent (e.g., that is functionally equivalent), even though notstructurally equivalent to the disclosed structure which performs thefunction in the herein illustrated exemplary implementations of thedisclosure. In addition, while a particular feature of the disclosuremay have been disclosed with respect to only one of severalimplementations, such feature may be combined with one or more otherfeatures of the other implementations as may be desired and advantageousfor any given or particular application. Furthermore, to the extent thatthe terms “includes,” “having,” “has,” “with,” or variants thereof areused in either the detailed description or the claims, such terms areintended to be inclusive in a manner similar to the term “comprising.”

The implementations have been described, hereinabove. It will beapparent to those skilled in the art that the above methods andapparatuses may incorporate changes and modifications without departingfrom the general scope of this invention. It is intended to include allsuch modifications and alterations in so far as they come within thescope of the appended claims or the equivalents thereof

What is claimed is:
 1. A tank assembly, comprising: a body comprising asidewall and a first end wall; and an antimicrobial liner comprising aneffective amount of an antimicrobial agent to inhibit growth ofmicroorganisms; wherein the antimicrobial liner covers an interiorsurface of the sidewall and an interior surface of the first end wall.2. The tank assembly of claim 1, the effective amount of theantimicrobial agent is in the range of 0.5% to 12% by weight of theantimicrobial liner.
 3. The tank assembly of claim 2, the antimicrobialagent comprising a silver based antimicrobial agent.
 4. The tankassembly of claim 1, the first end wall comprising an orifice formed toallow flow of fluid into and/or from the body.
 5. The tank assembly ofclaim 4, the antimicrobial liner comprising an orifice formed to allowalignment with the orifice of the first end wall.
 6. The tank assemblyof claim 4, comprising a flow diverter operably disposed at the orificeof the first end wall and configured to circulate fluid in the tankassembly.
 7. The tank assembly of claim 1, the body comprising a firstportion, comprising the first end wall, and a second portion, comprisinga second end wall of the body.
 8. The tank assembly of claim 7, theantimicrobial liner merely covering the interior surface of the sidewallin the first portion.
 9. The tank assembly of claim 7, the first portionconfigured to receive water and the second portion configured to receiveair, the first and second portions divided by a flexible bladder. 10.The tank assembly of claim 1, the antimicrobial liner comprising apolymer-based sheet formed to fit the internal shape of the body. 11.The tank assembly of claim 1, the antimicrobial liner comprising asubstantially smooth outer finish facing internally in the tank tomitigate microbial growth.
 12. The tank assembly of claim 1, theantimicrobial liner comprising a color, the color providing an indicatorof concentration of the antimicrobial agent present in the antimicrobialliner, wherein a darker color is indicative of a higher concentration.13. The tank assembly of claim 12, wherein the color is blue.
 14. Amethod of manufacturing a tank assembly constructing a tank bodycomprising a side wall and a first end wall; and installing anantimicrobial liner in the tank body so that the antimicrobial linercovers an interior surface of the sidewall and an interior surface ofthe first end wall; wherein the antimicrobial liner comprises aneffective amount of an antimicrobial agent to inhibit growth ofmicroorganisms.
 15. The method of claim 14, comprising constructing theantimicrobial liner with the effective amount of the antimicrobialagent, comprising adding an amount of the antimicrobial agent in therange of 0.5% to 12% by weight of the antimicrobial liner.
 16. Themethod of claim 15, the antimicrobial agent comprising a silver-basedagent in liquid or solid form.
 17. The method of claim 15, constructingthe antimicrobial liner comprising forming a polymer-based sheet in theshape of the interior surface of the sidewall and the interior surfaceof the first end wall.
 18. The method of claim 17, comprising mixing theantimicrobial agent with a polymer resulting in a antimicrobial agentand polymer mix, heating the mix resulting in a heated mix, forming theheated mix into a sheet, and forming the sheet.
 19. A tank assembly,comprising: A body comprising a side wall, a first interior potion, anda second interior portion, the first interior portion defined by theside wall, a first end wall, and a flexible membrane, the secondinterior portion defined by the side wall, a second end wall, and theflexible membrane, an orifice formed in the first end wall configured toprovide an entrance for a liquid; a valve disposed in the second endwall configured to provide an entrance for a gas; and an antimicrobialliner comprising an effective amount of an antimicrobial agent toinhibit growth of microorganisms, the antimicrobial liner covering aninterior surface of the sidewall and an interior surface of the firstend wall.
 20. The tank assembly of claim 19, the antimicrobial linercomprising a polymer-based material, and the effective amount of theantimicrobial agent comprising a silver-based agent in the range of 0.5%to 12% by weight of the antimicrobial liner.